81729266099672 has 16 divisors (see below), whose sum is σ = 162256631227560. Its totient is φ = 38460831105664.

The previous prime is 81729266099671. The next prime is 81729266099743. The reversal of 81729266099672 is 27699066292718.

It is a super-2 number, since 2×81729266099672² (a number of 29 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81729266099672.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81729266099671) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 300475242878 + ... + 300475243149.

Almost surely, 2^{81729266099672} is an apocalyptic number.

It is an amenable number.

81729266099672 is a deficient number, since it is larger than the sum of its proper divisors (80527365127888).

81729266099672 is a wasteful number, since it uses less digits than its factorization.

81729266099672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 600950486050 (or 600950486046 counting only the distinct ones).

The product of its (nonzero) digits is 493807104, while the sum is 74.

The spelling of 81729266099672 in words is "eighty-one trillion, seven hundred twenty-nine billion, two hundred sixty-six million, ninety-nine thousand, six hundred seventy-two".